Relationship between salivary lactoferrin level and brain amyloid load in periodontal and non-periodontal subjects

Abstract

BACKGROUND: Lactoferrin in saliva has been proposed as a possible diagnostic biomarker for Alzheimer's disease, as it is associated with ß-amyloid load in the brain. The aim of this study was to find out whether there is an association between salivary lactoferrin and cerebral ß-amyloid load and the involvement of periodontal disease in this possible connection. MATERIAL AND METHODS: Six exploratory comparison groups were designed: participants with mild cognitive impairment (n=50) (positive PET-amyloid with and without periodontal disease and negative PET-amyloid with and without periodontal disease) and cognitively normal older individuals with and without periodontal disease (n=19). All participants were recruited from referral hospitals in Granada, Spain, and from a nursing home in the same socio-economic area as the hospital participants. A salivary lactoferrin determination and a periodontal assessment has been performed in each of the participants. RESULTS: The results show that both having an atypical ß-amyloid load in the brain (PET+) and having periodontal disease are clearly associated with a lower concentration of salivary lactoferrin (p=0.011 and p=0.032), but not with age or gender. CONCLUSIONS: In this studio, the positive PET-amyloid and periodontal disease are related independently with lower lactoferrin levels.